/**
 * 获取上周、本周、上月、本月、上季度、本季度的开始日期、结束日期 start
 * 亲测无bug。获取上月开始结束日期考虑了年份的变化
 */
var now = new Date(); //当前日期
var nowDayOfWeek = now.getDay() - 1; //今天本周的第几天
var nowDay = now.getDate(); //当前日
var nowMonth = now.getMonth(); //当前月
var nowYear = now.getYear(); //当前年
nowYear += (nowYear < 2000) ? 1900 : 0; //
var lastMonthDate = new Date(); //上月日期
lastMonthDate.setDate(1);
lastMonthDate.setMonth(lastMonthDate.getMonth() - 1);
var lastYear = lastMonthDate.getYear();
var lastMonth = lastMonthDate.getMonth();
//格式化日期：yyyy-MM-dd
function formatDate(date) {
	var myyear = date.getFullYear();
	var mymonth = date.getMonth() + 1;
	var myweekday = date.getDate();
	if (mymonth < 10) {
		mymonth = "0" + mymonth;
	}
	if (myweekday < 10) {
		myweekday = "0" + myweekday;
	}
	return (myyear + "-" + mymonth + "-" + myweekday);
}
//获得某月的天数
function getMonthDays(myMonth) {
	var monthStartDate = new Date(nowYear, myMonth, 1);
	var monthEndDate = new Date(nowYear, myMonth+1, 1);
	var days = (monthEndDate - monthStartDate) / (1000 * 60 * 60 * 24);
	return days;
}
//获得本季度的开始月份
function getQuarterStartMonth() {
	var quarterStartMonth = 0;
	if (nowMonth < 3) {
		quarterStartMonth = 0;
	}
	if (2 < nowMonth && nowMonth < 6) {
		quarterStartMonth = 3;
	}
	if (5 < nowMonth && nowMonth < 9) {
		quarterStartMonth = 6;
	}
	if (nowMonth > 8) {
		quarterStartMonth = 9;
	}
	return quarterStartMonth;
}
//获得最近一周的开始日期  结束日期为当天日期
function getOneWeekStartDate(){
	var oneWeekDate=new Date(now-6*24*3600*1000);
	return formatDate(oneWeekDate);
}
//获得本周的开始日期
function getWeekStartDate() {
	var weekStartDate = new Date(nowYear, nowMonth, nowDay - nowDayOfWeek);
	return formatDate(weekStartDate);
}
//获得本周的结束日期
function getWeekEndDate() {
	var weekEndDate = new Date(nowYear, nowMonth, nowDay + (6 - nowDayOfWeek));
	return formatDate(weekEndDate);
}
//获得上周的开始日期
function getLastWeekStartDate() {
	var weekStartDate = new Date(nowYear, nowMonth, nowDay - nowDayOfWeek - 7);
	return formatDate(weekStartDate);
}
//获得上周的结束日期
function getLastWeekEndDate() {
	var weekEndDate = new Date(nowYear, nowMonth, nowDay - nowDayOfWeek - 1);
	return formatDate(weekEndDate);
}
//获得本月的开始日期
function getMonthStartDate() {
	var monthStartDate = new Date(nowYear, nowMonth, 1);
	return formatDate(monthStartDate);
}
//获得本月的结束日期
function getMonthEndDate() {
	var monthEndDate = new Date(nowYear, nowMonth, getMonthDays(nowMonth));
	return formatDate(monthEndDate);
}
//获得最近一月的开始日期
function getOneMonthStartDate(){
	var oneMonthStartDate = new Date(new Date(now-30*24*3600*1000));
	return formatDate(oneMonthStartDate);
}
//获得最近三个月的开始日期
function getThreeMonthStartDate(){
	var threeMonthStartDate = new Date(new Date(now-3*30*24*3600*1000));
	return formatDate(threeMonthStartDate);
}
//获得最近一年的开始日期
function getOneYearStartDate(){
	var oneYearStartDate = new Date(new Date(now-365*24*3600*1000));
	return formatDate(oneYearStartDate);
}
//获得上月开始时间
function getLastMonthStartDate() {
	if (lastMonth == 11) {
		var lastMonthStartDate = new Date(nowYear - 1, lastMonth, 1);
	} else {
		var lastMonthStartDate = new Date(nowYear, lastMonth, 1);
	}
	return formatDate(lastMonthStartDate);
}
//获得上月结束时间
function getLastMonthEndDate() {
	if (lastMonth == 11) {
		var lastMonthEndDate = new Date(nowYear - 1, lastMonth, getMonthDays(lastMonth));
	} else {
		var lastMonthEndDate = new Date(nowYear, lastMonth, getMonthDays(lastMonth));
	}
	return formatDate(lastMonthEndDate);
}
//获得本季度的开始日期
function getQuarterStartDate() {
	var quarterStartDate = new Date(nowYear, getQuarterStartMonth(), 1);
	return formatDate(quarterStartDate);
}
//获得本季度的结束日期
function getQuarterEndDate() {
	var quarterEndMonth = getQuarterStartMonth() + 2;
	var quarterStartDate = new Date(nowYear, quarterEndMonth,
		getMonthDays(quarterEndMonth));
	return formatDate(quarterStartDate);
}



//根据某年第几周获取开始日期
function getNumWeekStartDate(year,weeks){ 
	// 用指定的年构造一个日期对象，并将日期设置成这个年的1月1日 
	// 因为计算机中的月份是从0开始的,所以有如下的构造方法 
	var date = new Date(year,0,1); 
	// 取得这个日期对象 date 的长整形时间 time 
	var time = date.getTime(); 
	// 将这个长整形时间加上第N周的时间偏移 
	// 因为第一周就是当前周,所以有:weeks-1,以此类推 
	// 7*24*3600000 是一星期的时间毫秒数,(JS中的日期精确到毫秒) 
	time+=(weeks-1)*7*24*3600000; 
	date.setTime(time); 
	return formatDate(date); 
} 
//根据某年第几周获取结束日期
function getNumWeekEndDate(year,weeks){ 
	// 用指定的年构造一个日期对象，并将日期设置成这个年的1月1日 
	// 因为计算机中的月份是从0开始的,所以有如下的构造方法 
	var date = new Date(year,0,1); 
	// 取得这个日期对象 date 的长整形时间 time 
	var time = date.getTime(); 
	// 将这个长整形时间加上第N周的时间偏移 
	// 7*24*3600000 是一星期的时间毫秒数,(JS中的日期精确到毫秒) 
	time+=weeks*7*24*3600000; 
	date.setTime(time); 
	return formatDate(date); 
}
//获得去年今天的日期
function getLastYearToday(){
    var oneYearStartDate = new Date(nowYear-1,nowMonth,nowDay);
    return formatDate(oneYearStartDate);
}
//获得2年前今天的日期
function getLast2YearToday(){
    var oneYearStartDate = new Date(nowYear-2,nowMonth,nowDay);
    return formatDate(oneYearStartDate);
}
//获得当前日期
function getCurrentDate(){
    var oneYearStartDate = new Date();
    return formatDate(oneYearStartDate);
}

/**
 * 获取时间 end
 */
